Stacker for flexible sheet material



March 17, 1970 R fw. EMUS ETAL STACKER FOR FLEXIBLE SHEET MATERIAL 2 Sheets-Sheet 1 Filed Sept. 30, 1968 INVENTORS RONALD W EMUS BARRY W. STUART ATTORNEY March 17, 1970 w, us ETAL 3,500,780

' STACKER FOR FLEXIBLE SHEET MATERIAL Filed Sept. 30, 1968 2 Sheets-Sheet 2 INVENTORS RONALD W. EMUS BARRY W. STUART ATTORNEY BY Re W United States Patent STACKER FOR FLEXIBLE SHEET MATERIAL Ronald W. Emus, Greer, and Barry W. Stuart, Taylor's,

S.C., assignors to Southern Machinery Company, Greer,

S.C., a corporation of South Carolina Filed Sept. 30, 1968, Ser. No. 763,650 Int. Cl. D05b 33/02, 81/00 US. Cl. 112121.29 16 Claims ABSTRACT OF THE DISCLOSURE A versatile simplified and reliable stacker, for cloth articles and the like, characterized by few moving parts and the absolute minimum floor space occupation and being automatic in operation. The stacker may be used in conjunction with a sewing machine and/or thread cutting means if desired.

There has been a constant need in recent years in the apparel industry and in the manufacture of towels and certain other like articles for a truly reliable automatic stacker which is economical enough to justify its usage. Many different forms of stackers are known in the art including some which are quite sophisticated. However,

without exception, these prior art devices have been too expensive to be practical and require too much floor space in the manufacturing plant, which is the most vital consideration of all. In the manufacturing of towels and certain garments, in order for automatic stacking to be justified economically, the machine must be simple, trouble-free, and must take up very little floor space. It is believed that the present stacker fully satisfies these long-felt needs of the art. Other features and advantages will be apparent as the description proceeds.

Brief description of the drawings Description of the preferred embodiment Referring to the drawings in detail, wherein like numerals designate like parts, the numeral designates a supporting base which may be constructed of sheet metal having suitable framing and this base is characterized by being quite narrow in the direction of feed of the articles being handled and is designed generally to occupy the minimum possible floor space. The base 10 has a steeply sloping forward side wall 11 which forms one of the definite features of the invention, to be further described. A horizontal table member 12 is mounted upon the base 10 and is quite narrow, as shown in the drawings, in the direction of feed of the articles. This table top 12 in the embodiment shown may support a conventional sewing machine 13 of the type employed to produce a hem continuously along one edge of towels 14 or like cloth articles as they are advanced across the narrow table top in the manner shown. Normally, the stitching which hems the towels will connect them in a 3,500,780 Patented Mar. 17, 1970 continuous chain and such connecting threads may be severed by some form of automatic cutter on the table top close to the sewing machine and not shown herein for the purpose of simplicity. Such sewing and cutting combinations are known in the art and are not new broadly. The cutting to separate the articles 14 could be done manually. In some cases, the stacker could be employed without the sewing machine and previously separated articles could simply be fed continuously across the table top 12. However, the main utility of the invention will be in conjunction with a sewing machine and some form of automatic thread cutter to reduce the manual labor of stacking and allowing the sewing machine operator to continuously and rapidly hem the articles, after which they are automatically separated and stacked.

The stacker mechanism proper, which is extremely simple, comprises a horizontal stacker bar 15 parallel to the longitudinal axis of table member 12. This stacker bar is carried by a single vertically swingable support arm 16, secured at its lower end to a rocker shaft 17, journaled in suitable bearings 18 on base members 19. As best shown in FIGURE 2, a crank arm or link 20 rigid with the rocker shaft 17 extends inwardly of the base front wall 11 through a slot 21 and is pivotally connected at 22 to the piston rod 23 of an extensible and retractable fluid pressure operated cylinder unit 24 having its upper end pivoted at 25 to the front wall 11. The extension and retraction of the unit 24 is under control of a solenoid valve 26 mounted on one side of a relay box 27 on the rear side wall 28 of base 10. The connections between the valve 26 and cylinder 24 are conventional and need not be illustrated. The operation will be fully described. The unit 24 causes the arm 16 to swing back and forth at proper times between the positions shown in FIGURES 5a and 5b. In one position, the stacker bar 15 lies against the inclined front wall 11 close to the table top 12 and slightly therebelow, while in the other position the stacker bar and arm are spaced considerably forwardly of the table top.

In conjunction with the power unit 24 and associated controls, there is provided a sensing device preferably, but not necessarily, in the form of a microswitch 29 having an actuator rod 30 projecting forwardly through a long slot 31 in the front wall 11 of the base to facilitate adjustment of the sensing switch 29 to a wide variety of vertical positions measured from the table top 12. The switch is mounted on a bracket 32 having a permanent magnet 33 which holds the switch on the front wall 11 by magnetic attraction. This forms a very simple, reliable and versatile adjusting means for the sensing switch enabling it to be positioned precisely to accommodate towels and other articles of various lengths. In some instances, an adjustable photoelectric or like sensing means may be employed in lieu of the switch with its mechanical actuator element 30.

A second sensing element for the trailing end of the article 14 passing over the metal table top 12 is provided preferably in the form of a metal chain 34 suspended from the sewing machine head to one side of the needle. As long as the article 14 is between the chain 34 and table top 12, the chain is insulated from the table top and a control circuit is opened as will be described. When the trailing end of the article 14 passes out from under the chain, as depicted in FIGURE 6, an electrical circuit is established through the chain and table top.

A further feature of the invention resides in the provision of a small blower 35 immediately under the table top 12 and near the front wall 11, FIGURE 6. The utlet nozzle 36 of this blower is in registry with an opening 37 in a vertical flange 38 of the table top immediately beneath the horizontal top.

When the leading end of the article 14 engages the rod 30 and closes microswitch 29, the blower 35 is activated to assure the movement of the rear end of he article 14 over the bar 15. This is particularly necessary in the case of very light material which has a tendency to bunch or pucker on the table.

Operation The cycle of operation which is simple is most readily understood in connection with FIGURES 4 and 5a through 5d. These latter figures show the movements of the stacker bar 15 relative to the base and article 14 as a single article is stacked or draped over the bar. The control circuit producing the cyclic movement of the bar 15 is illustrated primarily in FIGURE 4.

As the article 14, such as a towel being sewn, passes under the chain 34 and separates the chain from the table top 12, a 12 volt relay 39 has its coil 40 de-energized bringing the relay contacts 41 to their normally closed position, as shown in FIGURE 4.

When the leading end of the article 14, FIGURE 5a, engages sensing switch actuator 30 and thereby closes the normally open switch 29, a circuit through the coil 42 of 110 volt relay 43 and through the contacts 41 of relay 39 is completed, causing the relay coil 42 to become energized.

When this occurs, the sets of contacts 43' and 43a in relay 43 are closed. Contact 43a, when closed, locks in the relay 43, so that in the event that microswitch 29 opens before the article 14 being sewn is completed, the entire circuit will not open. Contact 43a, when closed, causes solenoid valve 26 to be energized, immediately admitting air to the cylinder unit 24, FIGURE 2, and returning the bar 15 to rest against the front wall 11, as shown in FIGURE 5b.

When the sewing of the article is completed and its rear end passes from under the chain 34, a circuit is completed energizing the coil 40 of relay 39. When this happens, the relay contacts 41 open, breaking the circuit through the coil 42 of relay 43, opening contacts 43' and 43a, and subsequently de-energizing the coil of solenoid valve 26. This causes the stacker bar 15 to return to its outward position as in FIGURE 5d which is the same position shown in FIGURE 5a at the start of the stacking cycle. In FIGURE 4, the element 44 is a step-down transformer receiving 110 volts in with 12 volts out.

With bar 15 positioned as in FIGURES 5b and 5c and while the sewing operation is being completed, the trailing end portion of the article 14 is subjected to the air jet from blower 35 which is turned on automatically, as previously mentioned, when the leading end of the article 14 closes the sensing switch 29 and when the solenoid valve 26 is energized. This air jet blows the rear end portion of the article out over the bar 15 while in the position of FIG- URE 5b to assure the complete draping or stacking of the article on the bar as shown in FIGURE 50. When the bar 15 swings outwardly, FIGURE 5d, with the article 14 thereon, the apparatus is again conditioned for the next succeeding article being sewn and the cycle is repetitive indefinitely.

The steeply slanting front wall 11 plays an important role in the operation of the stacker. The article 14, which may be flimsy, will always slide downwardly upon the slanting wall and this movement will be aided by gravity because of the steepness of inclination of the wall. However, due to gravity, the article 14 will not hang freely and will not lose contact with the wall 11 and therefore will be guided by the slanting wall into contact with the sensing switch element 30. If the article were free-hanging from the edge of table top 12 and subject to the influence of air currents, it might not properly actuate the sensing switch.

As described, the magnet means 33 allows the switch 29 and actuator element 30 to be quickly adjusted to any position along the slot 31 which extends substantially for the entire height of the machine. This allows the machine to accommodate various sizes, shapes and types of cloth article with only one simple adjustment. The entire device is characterized by simplicity of construction and operation, compactness, and reliability and extreme economy. The advantages of the invention will be readily apparent to those skilled in the art.

It is to be understood that the form of the invention herein shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention.

What is claimed is:

1. A stacker for flexible sheet material articles comprising a base having a top over which the articles are slid in succession and also having an inclined front wall over which each article slides downwardly, a stacking bar rockably mounted near the bottom of the base and being swingable toward and away from the front wall to positions substantially contacting the front wall near and below the top of the base and outwardly of the front wall, a sensing device vertically adjustably mounted on the front wall and adapted to detect the presence of the leading end of each article passing downwardly over the front wall, and control and power means set into operation by the sensing device and having a connection with the stacking bar to shift the latter from an initial remote position relative to the inclined front wall to a position substantially against such wall.

2. A stacker in accordance with claim 1 wherein said sensing device includes an actuator element extending into the path of movement of each article descending over said front wall, said front wall having a substantially vertical slot receiving said actuator element, and a magnet mounting means for the sensing device supporting it adjustably relative to the slot on said front wall.

3. A stacker in accordance with claim 1 wherein the control and power means comprises a power actuator unit connected with the stacking bar for moving it toward and away from said front wall, and control circuit means including a solenoid-operated valve connected with the actuator unit and responsive to the sensing device when the sensing device senses the leading end of each article descending over said front wall.

4. Apparatus for handling and stacking flexible sheet material articles comprising a supporting base having a table top over which the articles move in succession, a stacker bar arranged at one side of the table top near the elevation of the table top and being substantially horizontal and substantially parallel to said one side of the table top, a vertically swingable arm carrying the stacker bar, power actuator means connected with said arm to cause movement of the stacker bar toward and away from said one side of the table top, a sensing means below the elevation of the table top and stacker bar and adapted to detect the leading end of each flexible article passing from said one side of the table top and depending therefrom, control circuit means connected with and responsive to the sensing means and connected with the power actuator means to operate the latter for moving the stacker bar from a first position spaced from said one side of the table top to a second position substantially against said one side, whereby the trailing portion of the article can then be fed over the stacker bar, and a second sensing means adjacent the table top engaging each article in succession passing over the table top and responding to disengagement with each article to energize the control circuit means and power actuator means, thereby causing the stacker bar to return to said first position.

5. Apparatus as defined by claim 4, wherein the sensing means is a switch mounted adjustably on the supporting base below the table top and having a switch actuator projecting into the path of movement of the leading end of each moving article hanging from said one side of the table top.

6. Apparatus as defined by claim 5, and wherein the power actuator means is an extensible and retractable power cylinder, and said control circuit means includes a solenoid-operated valve having a connection with said power cylinder and electrical relay means interconnecting the solenoid valve and switch.

7. Apparatus as defined by claim 6, wherein said second sensing means comprises a non-rigid conducting element in said control circuit means adapted to complete a circuit through the table top and causing the stacker bar to move to its first position spaced from said one side of the table top, each article while passing over the table top engaging under said non-rigid conducting element and insulating it from the table top and thereby opening the control circuit means and de-activating the power cylinder.

8. Apparatus as defined by claim 4, and a blower mounted on the apparatus near and below the elevation of the table top and directing a stream of air toward the side of the table top from which each article moves when passing over the stacker bar to assist said passing over, said blower set into operation when the sensing means detects said leading end of each acticle, said blower connected in said control circuit means.

9. An apparatus for sewing and stacking cloth articles and the like comprising a table means over which the articles may be fed in one direction with the leading ends of the articles descending over one edge of the table means, a sewing machine on the table means to produce stitching along at least one edge of each article passing over the table means, an electrical conducting element having a connection with the sewing machine and adapted to complete a circuit through the table means when disengaged from each article and separated from contact with the table means by each article passing thereunder during movement over the table means, a sensing means adjustably mounted upon the table means whereby its height relative to the top of the table means may be changed and having an element in the path of the leading end of each article descending from the top of the table means, a movable stacker member near one side of the table means shiftable toward and away from said one side responsive to operation of said conducting element and sensing means, a power actuator connected with said stacker member to shift the same, and a con trol circuit including an electrically operated control device for the power actuator, said control circuit connected with said conducting element and said sensing means.

10. The structure of claim 9, wherein the sensing means is a switch in said circuit having a projecting actuator element in the path of the leading end of each article descending from the top of the table means.

11. The structure of claim 10, wherein the conducting element is a length of chain depending freely from the sewing machine.

12. The structure of claim 9, and a blower device on the table means near the top thereof and connected in said control circuit and operable in response to said Sensing means detecting the leading end of each article and directing an air stream toward the stacker member and away from the side of the table means from which each article passes onto the stacker member when the stacker member is substantially against such side.

13. The structure of claim 9, wherein the control circuit comprises a first relay having a connection with the table means and with the electrical conducting element and also having a connection with the sensing means, and a second relay having an electrical connection with the sensing means and with said electrically operated control device for said power actuator.

14. The structure of claim 13, wherein the sensing means is a switch interconnecting contacts of the first and second relays, said switch being normally open and said switch having an actuator in the path of movement of the leading end of each article and closing said switch upon contact with such leading end.

15. The structure of claim 14, and wherein the second relay contains plural contacts including a pair of relay latching contacts preventing opening of the control circuit in the event said switch opens prematurely before completion of the sewing operation on each article.

16. An apparatus for stacking comprising a table-like support over which flexible sheet material articles may slide in succession with the leading end of each article passing downwardly from one edge of the support, a stacker bar element mounted near said one edge of the support and movable toward and away from said one edge, power means rockably supporting said bar element and adapted to move the same toward and away from said one edge of the support, a sensing element arranged below the elevation of the stacker bar element and being vertically adjustable and being in the path of movement of the leading edge of each article descending from said one edge of the support, a second sensing element associated with the support and adapted to complete an electrical circuit through a part of the support and held out of electrical contact with said part of the support by said articles passing thereunder, and electrical control circuit means connected with the power means and said first and second-named sensing elements whereby the latter may cyclically cause shifting of the stacker bar element toward and away from said one edge of the support.

References Cited UNITED STATES PATENTS 2,060,511 11/1936 Learnard et a1. 112-12129 XR 2,151,136 3/1939 Moffitt 112-12129 XR 2,788,967 4/1957 Jesus 112-12129 XR 3,219,001 11/1965 Spivey et a1.

3,371,631 3/1968 Rockerath 83-83 XR FOREIGN PATENTS 1,021,888 3/1966 Great Britain.

JAMES R. BOLER, Primary Examiner US. Cl. X.R. 83-83 

